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White noise. I bought a white noise machine years ago when I lived near a large emergency room that had ambulances going by all day every day. It really helped with the sirens, and when I moved away I kept using the machine. My brain now interprets the white noise as profound silence, and I sleep so deeply that I don’t know how I ever got by without it.
Mike Duncan’s Revolutions podcast (especially series 3 covering the French Revolution) and his The History of Rome series.